CN211184328U - Dimming system - Google Patents
Dimming system Download PDFInfo
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- CN211184328U CN211184328U CN201921775267.2U CN201921775267U CN211184328U CN 211184328 U CN211184328 U CN 211184328U CN 201921775267 U CN201921775267 U CN 201921775267U CN 211184328 U CN211184328 U CN 211184328U
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Abstract
The present application relates to a dimming system comprising a power module, a light emitting device, a switching circuit and a diode; the first end of the power supply module is connected with the first end of the light-emitting device; the second end of the light-emitting device is connected with the first end of the switch circuit; the switching circuit can convert the direct-current voltage output by the power supply module into square-wave voltage with variable duty ratio; the second end of the switch circuit is connected with the second end of the power supply module; the first end of the diode is connected with the first end of the power supply module; and the second end of the diode is connected with the first end of the switching circuit, wherein the polarity of the first end of the diode is opposite to that of the first end of the power supply module, and the diode is used for reducing the voltage stress of an electronic device in the dimming system.
Description
Technical Field
The application relates to the field of electrical control, in particular to a dimming system.
Background
Modern agricultural plant cultivation can use an L lighting Diode (L ED) lamp instead of sunlight except for a traditional sunlight cultivation mode, and plants can be subjected to photosynthesis under the light irradiation of the L ED lamp.
Meanwhile, most L ED driving power supplies are in constant-current output, each driving power supply is connected with a group of L ED lamps, namely a L ED driving power supply is arranged in a L ED lamp, and meanwhile, the L ED lamp also needs to have a dimming function according to the plant growth requirement in a plant factory.
In the prior art, when the brightness of the L ED lamp is adjusted by a PWM dimming technology, a L ED lamp does not continuously emit light, but a L ED lamp is applied with a pulse signal with a certain duty ratio to continuously turn on and off the L ED lamp, when the on and off are alternately fast, the eye can think that an L ED lamp is always on, the longer the off state lasts, the lower the brightness is the visual perception of the L ED lamp to the eye, the longer the on state lasts, the time of the off state is correspondingly reduced, and the L ED lamp is turned on.
SUMMERY OF THE UTILITY MODEL
The technical problem that when the PWM is used for dimming, L ED lamps and other electronic devices in a circuit system bear high voltage stress, and L ED lamps and electronic devices in the lamps are easily damaged due to the fact that a large parasitic inductance value exists on a line due to a high-frequency-change pulse signal in the prior art is solved.
In order to solve the technical problem, an embodiment of the present application discloses a dimming system, which includes a power module, a light emitting device, a switching circuit, and a diode;
the first end of the power supply module is connected with the first end of the light-emitting device;
the second end of the light-emitting device is connected with the first end of the switch circuit; the switching circuit can convert the direct-current voltage output by the power supply module into square-wave voltage with variable duty ratio;
the second end of the switch circuit is connected with the second end of the power supply module;
the first end of the diode is connected with the first end of the power supply module;
and the second end of the diode is connected with the first end of the switching circuit, wherein the polarity of the first end of the diode is opposite to that of the first end of the power supply module, and the diode is used for reducing the voltage stress of an electronic device in the dimming system.
Optionally, the dimming system further comprises a resistor; the first end of the resistor is connected with the second end of the diode, and the second end of the resistor is connected with the first end of the switch circuit; or the first end of the resistor is connected with the first end of the power supply module, and the second end of the resistor is connected with the first end of the diode.
Optionally, the switching circuit includes a transistor switch, and the switching circuit is configured to convert the dc voltage output by the power supply module into a square wave voltage with a variable duty ratio based on a control signal received by a control terminal of the transistor switch.
Optionally, the transistor switch may be any one of a field effect transistor, a triode, and an insulated gate bipolar transistor.
Optionally, the dimming system further comprises a current limiting circuit;
the first end of the current limiting circuit is connected with the second end of the light-emitting device; the second end of the current limiting circuit is connected with the first end of the switch circuit; the current limiting circuit can limit a current passing through the light emitting device within a range of equal to or less than a reference current.
Optionally, the dimming system includes one or more series-connected current limiting circuits and the light emitting device, and the plurality of series-connected current limiting circuits and the light emitting device are connected in parallel.
Optionally, the current limiting circuit includes an operational amplifier circuit, a first resistor R1, a second resistor R2, a first capacitor C, and a tuning tube Q2;
the inverting input end of the operational amplification circuit is respectively connected with the first end of the first resistor R1 and the first end of the first capacitor, and the non-inverting input end of the operational amplification circuit is used for receiving a reference signal;
the second end of the first capacitor C is connected with the first end of the second resistor R2;
the output end of the operational amplification circuit is respectively connected with the second end of the second resistor R2 and the control end of the adjusting tube Q2;
the first end of the adjusting tube Q2 is connected with the second end of the light-emitting device;
the second end of the adjusting tube Q2 is connected with the first end of the first resistor R1;
the second end of the first resistor R1 is connected with the first end of the switch circuit;
the current limiting circuit is used for limiting the current passing through the light-emitting device within a range smaller than or equal to a reference current corresponding to the reference signal.
Optionally, the dimming system comprises one or more light emitting devices, and the plurality of light emitting devices are connected in parallel.
Optionally, the light emitting device comprises 1L ED light emitting device or a plurality of L ED light emitting devices in series.
Optionally, the distance between the power module and the light emitting device is greater than or equal to 1 meter.
The dimming system comprises a power supply module, a light-emitting device, a switching circuit and a diode; the first end of the power supply module is connected with the first end of the light-emitting device; the second end of the light-emitting device is connected with the first end of the switch circuit; the switching circuit can convert the direct-current voltage output by the power supply module into square-wave voltage with variable duty ratio; the second end of the switch circuit is connected with the second end of the power supply module; the first end of the diode is connected with the second end of the power supply module; the second end of the diode is connected with the first end of the switching circuit, wherein the polarity of the first end of the diode is opposite to that of the first end of the power supply module, and the diode is used for reducing the voltage stress of an electronic device in the dimming system; therefore, a loop can be formed between the light-emitting device and the diode, and when the switching circuit is switched off, the voltage stress of an electronic device in the dimming system can be reduced.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.
Fig. 1 is a schematic structural diagram of a dimming system according to an embodiment of the present application;
fig. 2 is a schematic structural diagram of a dimming system according to an embodiment of the present application;
fig. 3 is a schematic structural diagram of a dimming system according to an embodiment of the present application;
fig. 4 is a schematic structural diagram of a dimming system according to an embodiment of the present application;
fig. 5 is a schematic structural diagram of a dimming system according to an embodiment of the present application;
fig. 6 is a schematic diagram of a dc voltage output by a power module in a dimming system according to an embodiment of the present application;
fig. 7 is a schematic diagram illustrating that a dc voltage output by a power module in a dimming system according to an embodiment of the present application is converted into a square wave voltage with a variable duty ratio;
the following is a supplementary description of the drawings:
1-a power supply module; 2-a light emitting device; 3-a switching circuit; 4-a diode; 5-resistance; 6-current limiting circuit.
Detailed Description
The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. It is to be understood that the embodiments described are only a few embodiments of the present application and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
Reference herein to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic may be included in at least one implementation of the present application. In the description of the present application, it is to be understood that the terms "upper", "lower", "top", "bottom", and the like, indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are only for convenience in describing the present application and simplifying the description, and do not indicate or imply that the referred devices or elements must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present application. Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. Moreover, the terms "first," "second," and the like are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the application described herein are capable of operation in sequences other than those illustrated or described herein.
Referring to fig. 1, fig. 1 is a schematic structural diagram of a dimming system according to an embodiment of the present disclosure; the dimming system comprises a power module 1, a light-emitting device 2, a switching circuit 3 and a diode 4;
a first end of the power module 1 is connected with a first end of the light emitting device 2;
a second terminal of the light emitting device 2 is connected to a first terminal of the switching circuit 3; the switching circuit 3 can convert the direct-current voltage output by the power module 1 into square-wave voltage with variable duty ratio;
the second end of the switch circuit 3 is connected with the second end of the power supply module 1;
the first end of the diode 4 is connected with the first end of the power module 1;
a second terminal of the diode 4 is connected to the first terminal of the switching circuit 3, wherein a polarity of the first terminal of the diode 4 is opposite to a polarity of the first terminal of the power module 1, and the diode 4 is used for reducing a voltage stress of an electronic device in the dimming system.
Optionally, the second end of the power module 1 is a negative electrode, and in this design, an isolation element is not required to be arranged when the switching circuit 3 is driven, so that the driving signal of the switching circuit 3 can be conveniently obtained.
The dimming principle of the dimming system is as follows: when dimming, the switching circuit 3 is in a normally closed mode, and when dimming, the switching circuit 3 operates in an on-off mode, that is, the switching circuit 3 operates in an alternate off mode and on mode, and thus the current on the light emitting device 2 exhibits a square wave current; the duty ratio of the square wave current varies with the variation of the duty ratio of the dimming signal, and the average value of the current of the light emitting device 2 varies with the variation of the duty ratio, thereby achieving the purpose of uniform dimming.
In the embodiment of the present application, please refer to fig. 2, fig. 2 is a schematic structural diagram of a dimming system provided in the embodiment of the present application; the dimming system of fig. 1 further comprises a resistor 5; the dimming system further comprises a resistor 5; a first end of the resistor 5 is connected with a second end of the diode 4, and a second end of the resistor 5 is connected with a first end of the switch circuit 3; or the first end of the resistor 5 is connected with the first end of the power module 1, and the second end of the resistor 5 is connected with the first end of the diode 4.
In an alternative embodiment, the switch circuit 3 includes a transistor switch, and the switch circuit 3 is configured to convert the dc voltage output by the power module 1 into a square wave voltage with a variable duty ratio based on a control signal received by a control terminal of the transistor switch.
Optionally, the transistor switch may be any one of a field effect transistor, a triode, and an insulated gate bipolar transistor.
In the embodiment of the present application, please refer to fig. 3, fig. 3 is a schematic structural diagram of a dimming system provided in the embodiment of the present application; the dimming system of fig. 1 further comprises a current limiting circuit 6;
a first terminal of the current limiting circuit 6 is connected to a second terminal of the light emitting device 2; the second end of the current limiting circuit 6 is connected with the first end of the switch circuit 3; the current limiting circuit 6 can limit the current passing through the light emitting device 2 within a range of equal to or less than the reference current. Optionally, the second end of the power module 1 is a negative electrode, and in this design, an isolation element is not required to be arranged when the switching circuit 3 is driven, so that the driving signal of the switching circuit 3 can be conveniently obtained.
In an alternative embodiment, the current limiting circuit 6 includes an operational amplifier circuit, a first resistor R1, a second resistor R2, a first capacitor C, and a regulating tube Q2;
the inverting input end of the operational amplification circuit is respectively connected with the first end of the first resistor R1 and the first end of the first capacitor C, and the non-inverting input end of the operational amplification circuit is used for receiving a reference signal;
the second end of the first capacitor C is connected with the first end of the second resistor R2;
the output end of the operational amplification circuit is respectively connected with the second end of the second resistor R2 and the control end of the adjusting tube Q2;
a first end of the adjusting tube Q2 is connected with a second end of the light-emitting device 2;
the second end of the adjusting tube Q2 is connected with the first end of the first resistor R1;
a second terminal of the first resistor R1 is connected to a first terminal of the switch circuit 3;
the current limiting circuit 6 is configured to limit a current passing through the light emitting device 2 to be equal to or less than a reference current corresponding to the reference signal.
The working principle of the current limiting circuit 6 in the embodiment of the application is that the adjusting tube works in a linear state, and the resistance of the adjusting tube are changed along with the magnitude of a control signal of a control end of the adjusting tube; the electric signals at two ends of the first resistor are collected, voltage is input to the inverting input end of the operational amplifying circuit U, the voltage is compared with the reference signal Vref of the non-inverting input end, when the collected electric signals are smaller than the reference set signal, the electric signals at the output end of the operational amplifying circuit rise, the adjusting tube is an MOS tube for example, the voltage input to the grid electrode of the MOS tube rises, the resistance between the drain and the source of the MOS tube is reduced, the total resistance value of the branch of the serially connected light-emitting device 2 and the current limiting circuit 2 is reduced, the current of the branch is increased, and therefore the electric signals are adjusted to be close to or equal to the reference current corresponding to the reference signal Vref.
In the embodiment of the present application, please refer to fig. 4, fig. 4 is a schematic structural diagram of a dimming system provided in the embodiment of the present application; the dimming system in fig. 1 may include one series connection of the current limiting circuit 6 and the light emitting device 2 or a plurality of series connections of the current limiting circuit 6 and the light emitting device 2, and the plurality of series connections of the current limiting circuit 6 and the light emitting device 2 are connected in parallel.
In the embodiment of the present application, the dimming system comprises one or more light emitting devices 2, and a plurality of light emitting devices 2 are connected in parallel, optionally, the light emitting devices 2 comprise 1L ED light emitting device 2 or a plurality of L ED light emitting devices 2 connected in series, and compared with connecting one light emitting device 2 and a switch circuit 3 to each power supply device, the cost of the power supply device and the switch circuit 3 can be reduced by sharing one power supply device and one switch circuit 3 with a plurality of light emitting devices 2.
In the embodiment of the present application, optionally, the distance between the power module 1 and the light emitting device 2 is greater than or equal to 1 meter. A certain distance is reserved between the light-emitting device 2 and the power module 1, so that the working environment temperature of the light-emitting device 2 and the working environment temperature of the power module 1 are not too high, and the service lives of the light-emitting device 2 and the power module 1 can be prolonged to a certain extent.
Based on the above explanation, an alternative embodiment is described below, taking the example where the light emitting device is a light emitting diode, the transistor switch is an N-channel MOSFET, and the trim transistor is an N-channel MOSFET.
Referring to fig. 5, fig. 5 is a schematic structural diagram of a dimming system according to an embodiment of the present disclosure; the dimming system comprises a power supply module 1, a transistor switch Q1, a light emitting diode D, a diode 4 and a current limiting circuit 6;
a second terminal (negative terminal) of the power module 1 is connected to a second terminal (source) of the transistor switch Q1;
a first terminal (drain) of the transistor switch Q1 is connected to the current limiting circuit 6; the transistor switch Q1 is configured to convert a dc voltage output by the power module 1 into a square wave voltage with a variable duty ratio based on a control signal received by a control terminal of the transistor switch; optionally, the control terminal of the transistor switch in the embodiment of the present application may be a gate-source input terminal.
The current limiting circuit 6 comprises an operational amplifier circuit U, a first resistor R1, a second resistor R2, a first capacitor C and a regulating tube Q2;
the inverting input end of the operational amplification circuit U is connected to the first end of the first resistor R1 and the first end of the first capacitor C, respectively, and the non-inverting input end of the operational amplification circuit U is used for receiving a reference signal Vref;
the second end of the first capacitor C is connected with the first end of the second resistor R2;
the output end of the operational amplification circuit U is respectively connected with the second end of the second resistor R2 and the control end (grid) of the adjusting tube;
the second end (source electrode) of the adjusting tube is connected with the first end of the first resistor R1;
a second terminal of the first resistor R1 is connected to a first terminal of the switch circuit 3, i.e. a first terminal (drain) of a transistor switch Q1;
the first end (drain) of the adjusting tube is connected with the second end of the light-emitting device 2;
the first end of the light emitting device 2 is connected to the first end (positive end) of the power module 1;
a second terminal (anode) of the diode 4 is connected to a first terminal (drain) of the transistor switch Q1;
a first terminal (negative pole) of the diode 4 is connected to a first terminal (positive pole) of the power module 1, wherein the current limiting circuit 6 is configured to limit a current passing through the light emitting device 2 within a range of a reference current corresponding to the reference signal Vref or less, and the diode 4 is configured to reduce a voltage stress of an electronic device in the dimming system. Referring to fig. 6, fig. 6 is a schematic diagram of a dc voltage output by a power module 1 in a dimming system according to an embodiment of the present disclosure, where the power module 1 outputs an electrical signal with a stable amplitude, and the electrical signal may be a dc voltage signal or a dc current signal.
Referring to fig. 7, fig. 7 is a schematic diagram illustrating that the dc voltage output by the power module in the dimming system is converted into the square wave voltage with the variable duty ratio, when the switching circuit 3 is turned off, the amplitude of the pulse signal is 0, and a loop can be formed between the light emitting device 2 and the diode 4, so as to reduce the voltage stress of the electronic device in the dimming system, where the voltage stress can be a back electromotive force formed by the varying square wave voltage.
The above description is only exemplary of the present application and should not be taken as limiting the present application, as any modification, equivalent replacement, or improvement made within the spirit and principle of the present application should be included in the protection scope of the present application.
Claims (10)
1. A dimming system, characterized in that it comprises a power supply module (1), a light emitting device (2), a switching circuit (3) and a diode (4);
the first end of the power supply module (1) is connected with the first end of the light-emitting device (2);
the second end of the light-emitting device (2) is connected with the first end of the switch circuit (3); the switching circuit (3) can convert the direct-current voltage output by the power supply module (1) into a square wave voltage with a variable duty ratio;
the second end of the switch circuit (3) is connected with the second end of the power supply module (1);
the first end of the diode (4) is connected with the first end of the power supply module (1);
the second end of the diode (4) is connected with the first end of the switch circuit (3), wherein the polarity of the first end of the diode (4) is opposite to that of the first end of the power supply module (1), and the diode (4) is used for reducing the voltage stress of the electronic device in the dimming system.
2. A dimming system as claimed in claim 1, characterized in that the dimming system further comprises a resistor (5); a first end of the resistor (5) is connected with a second end of the diode (4), and a second end of the resistor (5) is connected with a first end of the switch circuit (3); or the first end of the resistor (5) is connected with the first end of the power supply module (1), and the second end of the resistor (5) is connected with the first end of the diode (4).
3. The dimming system according to claim 1, wherein the switching circuit (3) comprises a transistor switch, and the switching circuit (3) is configured to convert the dc voltage output by the power module (1) into a square wave voltage with a variable duty cycle based on a control signal received by a control terminal of the transistor switch.
4. A dimming system as claimed in claim 3, wherein the transistor switch is any one of a field effect transistor, a triode and an insulated gate bipolar transistor.
5. A dimming system as claimed in claim 1, further comprising a current limiting circuit (6);
a first end of the current limiting circuit (6) is connected with a second end of the light emitting device (2); the second end of the current limiting circuit (6) is connected with the first end of the switch circuit (3); the current limiting circuit (6) is capable of limiting a current through the light emitting device (2) to a range of less than or equal to a reference current.
6. The dimming system according to claim 5, wherein the dimming system comprises one series connection of the current limiting circuit (6) and the light emitting device (2) or a plurality of series connections of the current limiting circuit (6) and the light emitting device (2), and the plurality of series connections of the current limiting circuit (6) and the light emitting device (2) are connected in parallel.
7. The dimming system according to claim 5, wherein the current limiting circuit (6) comprises an operational amplifier circuit, a first resistor R1, a second resistor R2, a first capacitor C and a regulating tube Q2;
the inverting input end of the operational amplifier circuit is respectively connected with the first end of the first resistor R1 and the first end of the first capacitor, and the non-inverting input end of the operational amplifier circuit is used for receiving a reference signal;
the second end of the first capacitor C is connected with the first end of the second resistor R2;
the output end of the operational amplification circuit is respectively connected with the second end of the second resistor R2 and the control end of the adjusting tube Q2;
the first end of the adjusting tube Q2 is connected with the second end of the light-emitting device (2);
the second end of the adjusting tube Q2 is connected with the first end of the first resistor R1;
the second end of the first resistor R1 is connected with the first end of the switch circuit (3);
wherein the current limiting circuit (6) is used for limiting the current passing through the light-emitting device (2) within a range of less than or equal to the reference current corresponding to the reference signal.
8. A dimming system as claimed in claim 1, characterized in that the dimming system comprises one or more light emitting devices (2), a plurality of the light emitting devices (2) being connected in parallel.
9. Dimming system according to claim 1, characterized in that the light emitting device (2) comprises 1L ED light emitting device (2) or a plurality of L ED light emitting devices (2) in series.
10. Dimming system according to claim 1, characterized in that the distance between the power supply module (1) and the lighting device (2) is greater than or equal to 1 meter.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201921775267.2U CN211184328U (en) | 2019-10-22 | 2019-10-22 | Dimming system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201921775267.2U CN211184328U (en) | 2019-10-22 | 2019-10-22 | Dimming system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN211184328U true CN211184328U (en) | 2020-08-04 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201921775267.2U Active CN211184328U (en) | 2019-10-22 | 2019-10-22 | Dimming system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN211184328U (en) |
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2019
- 2019-10-22 CN CN201921775267.2U patent/CN211184328U/en active Active
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